protheroe



No. 626,345. Patented June 6, I899.

C. C. PRUTHEROE.

MECHANICAL MOVEMENT.

(Application filed Dec. 12, 1898.)

3 Sheets-Shaet I.

(No Model.)

INVENTUR Qua-L ATTORNEY WITN ESSES:

No. $26,345. Patented June 6, I899.

c. c. PROTHEROE.

MECHANICAL MOVEMENT:

(Application filed Dec. 12, 1898.) (No Model.) 3 Sheets-Sheet 2.

WITNESSES: lNVENTOR '4 ATTORNEY No. 626,345. Patented June 6, I899.

C. G. PRUTHEBDE.

MECHANICAL MOVEMENT.

(Application filed. Dec. 12, 1898.) (No Model.) 3 Sheets-Sheet WITNESES:INVENTOR M BY NlTFD STATES CHARLES C. PROTI'IEROE, OF NElV YORK, N. Y.

MECHANICAL MOVEM ENT.

SPECIFICATION forming part of Letters Patent No. 626,345, dated June 6,1899.

Application filed December 12, 1898. Serial No. 698,965- (No model.)

To ctZZ whom it may concern:

Be it known that I, CHARLES C.PROTHEROE, of Richmond Hill, borough ofQueens, city and State of New York, have invented a new andusefullmprovementin Mechanical Movements, of which the following is aspecification.

My invention relates to a mechanical movement whereby motion or powermay be transmitted, and more particularly to a lever and a fulcrumtherefor, the said fulcrum being movableandcontrolledbytheleveritself.Thesaid fulcrum is preferably a ball which is positively reciprocatedover its pat-h by the controllinglever. \Vith such a lever and fulcrumare combined a driving-crank and a driven crank, the lever then actingto communicate the motion of the one to the other. Preferably, however,there are employed a crank having an invariable throw, whereby rotarymotion is imparted to one end of said lever, and a crank of variablethrow, which is rotated by the other end of said lever, by which meansthe motion of the driven crank is caused to synchronize substantiallyand sufficiently for practical purposes with the motion of thedriving-crank.

The aforesaid combination of lever, fulcrum, and cranks is shown hereinas specifically embodied in the driving mechanism of a bicycle, to whichit is particularly well adapted.

In the accompanying drawings, Figures 1, 2, and 3 are side elevations ofmy mechanical movement, showing the lever in three positions. Fig. i isa top View. Fig. ,5 is an illustrative detail View showing the lever inthe position represented in Fig. 1 and the ball in section. Fig. 6 is avertical cross-section on the line a: so of 2. Fig. 7 is a similarcrosssection showing a rollerfulcrum substituted for the ball. Fig. 8shows my mechanical motion applied to power transmission in a bicycle.Fig. 9 shows the same on a larger scale than in Fig. 8, certain partsbeing broken away and the mechanism being viewed from the side oppositeto that shown in Fig. 8.

Similar letters and numbers of reference indicate like parts.

Referring first to Figs. 1 to (3, inclusive, A is a supporting-bar. B isa shaft journaled near one end of said bar and having a crankarm C. D isa gear or pulley, the shaft E of which is journaled near the oppositeend of said bar. In the pulley or gear D is aradial slot or guideway F.

G is a lever connected at one end to the pin H of crank C and carryingat the other end a pin 1, which projects at right angles from said leverand is received in the slot or guideway F in gear D. i

In the bar A is a longitudinal slot J. Supported on bar A by the arms Lis a plate M, which is parallel to the side face of bar A and has in ita slot J, similar to slot J. K is a ball, preferably of hardened steel.The difference between'the face of bar A and the opposite face of plateM is less than the diameter of said ball. I-Ience said ball whileentering said slots J J is supported by and freely rolls along the edgesof said slots, as shown particularly in Fig. 6. So, also, the diameterof said ball is greater than the transverse width of either slot J J.Hence said ball is prevented from coming through said slots, or, inother words, is retained between the plate M and bar A, while free tomove to and fro in the guideway formed by said slots.

The connecting-lever 0 passes between the bar A and the plate M and hasformed in it a longitudinal slot 0, which is of suitable transversewidth to receive in it the ball K. It will be understood, therefore,that said ball liesin slot 0 and also in slots or guideways J J.

It will be obvious that when either end of the lever G is moved over acurvilinear path, as by the rotation of crank O or gear D, said leverwill have a movement of translation and also a vibratory movement aroundthe ball K as a fulcrum. As the said ball, however, is free to move inthe guide-slots J J", it will be moved to and fro in said slots by theaction upon it of an advancing edge of the slot 0 in the lever G. Thiswill be better understood from Fig. 5. Thus assuming the lever G is inthe position shown in and is moving to the left of that figure, asindicated by the arr0ws,while also turning on said ball as a fulcrum, itis obvious that the edge a of the slot 0 is the advancing edgepositively acting upon a point on the spherical surface of said ball,and thus causing said ball to roll to the left in its guide-slots J J.,If, on the other hand, we consider in the same figure that the lever Gis moving to the right,while turning on the ball as a fulcrum, then theedge I) of the slot 0 would be the advancing edge positively acting, asbefore.

Now referring to Figs. 1, 2, and 3 and considering the lever G, asshown, attached to the crank-arm C and said arm to rotate in thedirection of the arrow in Fig. 1, the advancing edge I) of the slot 0 inlever G will roll the ball to the right in the guideways J J; but theedges of slot 0 are now constantly approaching parallelism to those ofslots J J, and when the lever reaches the position shown in Fig. 2 theybecome parallel, or, in other words, the longitudinal component of forceacting on the ball K disappears and the onward motion of the ballceases. As the crank continues its rotation the lever G moves intheopposite direction that is, to the leftand as it turns on the ball asa fulcrum the slot 0 presents again an advancing edge, which carries theball to the left. Hence the ball is caused to make an excursion in theguideways J J forward and back for each rotation of the crank C. It willbe obvious that the transverse edges c of the slot 0 do not necessarilystrike the ball, nor is the ball in its excursion necessarily carriedagainst the transverse edges d of the slots J J. The means whereby itstravel in the guideways J J is limited and controlled is solely thelever G, of which it is a rolling fulcrum, while it will always adjustitself to suit the movement of that lever.

Recurring again to Figs. 1, 2, and 3, it will be observed that thelength of lever Gbetween the centers of pin 1' and crank-pin His thereshown as greater than the distance betweenthe centers of crank-shaft Band gearshaft E. The pin I at the end of lever Gbeing also free to movein the slot F in gear D, the rotary motion of the crank C may thereforebe transmitted to the gear D, so that the movement of a point on thecircumference of gear D may synchronize with the movement of thecrank-pin H with sufficient approximation to permit this arrangement ofthe invention to be utilized under conditions where it isdesirable thatuniform rotary motion of the driving-shaft should cause approximatelycorresponding uniform rotary motion of the driven shaft. Such anapplication of my invention liesin its embodiment in a bicycle,

one way of accomplishing which is disclosed in Figs. 8 and 9.

1, 2, and 3 are members of the bicycle-' frame. a V

4 is the rear or driving wheel, having on its axle a pinion 5. I r

6 and 7 are pedal-cranks. Projecting rear ward from the pedal-crankshaftbearing is a bar 8, which has in it the elongated slot J. Projectingforward from the rear member of the frame is a bar 9, in which is theelongated slot J The bars 8' and 9' are connected by a cross-arm L,which is here shown as forged integral with said bars, but which may bea separate piece and detachably secured to said bars or made integralwith one bar and detachably secured to the other in any suitable way.The gear D is a toothed pinion, having its shaft E journaled in bar 9and engaging with the pinion 5 on the driving-axle. The lever G issecured at one end to the crankpin II on the pedal-crank 6 and the pin Ienters the slot F in pinion D, as already de scribed. The ball K isreceived in the slots J J and in the slot 0 in lever G.

When the pedal-cranks 6 and 7 are operated by the rider in the ordinaryway, rotary motion is communicated through the lever G to the pinion Dand so to pinion 5, whereby the driving-wheel'is turned in direction topropel the machine. 7

At the ends of the slots JJ, I may provide buffers I, of rubber,leather, or other elastic material, to receive any chance impact of theball K in case of its abnormal displacement.

So, also, I may apply similar buffers Q at the ends of the slot F ingear D to receive the impact of'pin I in case of necessity.

Although I deem the ball-fulcrum as prefable, I may employ aroller-fulcrum R, received in slots J J and O, as represented in Fig 7.In order to. keep the axis of this roller truly at right angles to itsline of movement, I provide washers S, which washers bear on the bar Aand plate M.

By combining the lever with a crank having a variable throw and alsowith the con trolled movable fulcrum, as hereinbefore described, Isecure a more nearly approximate .synchronism between the driving andthe driven cranks than is obtainable by the use of either the crank withthe variable throw or th controlled movable fulcrum separately.

A claim 1. In a mechanical movement, two mechanical members, (eachhaving a guideway) in combination with a loose ball received andretained in both of said guideways, whereby one of said members ispermitted a movement of vibration around said ball as a fulcrum, andalso of translation in a plane passing through its own longitudinalaxis, substantially as described.-

2. Inamechanical movement, two mechanical members each having aguideway, in combination with a loose ball received and retained in bothof said guideways; whereby one of said members is permitted amovementand also of translation in a plane passing through its own longitudinalaxis, and a driving-crank and a driven crank connected to saidlast-named member.

3. In a mechanical movement, a crank having an invariable throw, a crankhaving a variable throw, a lever connected at its ends respectively tosaid cranks, anda fulcrum for said lever; the said fulcrum being movofvibration around said ball as a fulcrum,

able relatively to said lever and controlled by the movement of saidlever, substantially as described.

4. In a mechanical movement, two cranks, a lever pivoted at its end toone of said cranks, a movable connection joining the other end of saidlever to the other crank whereby said end is compelled to move radiallyto the crankshaft, and a movable fulcrum for, and controlled by themovement of, said lever, substantially as described.

5. In a bicycle, a pedal-crank, a gear actuating the driving-axle, aleverhavingalongitudinal slot attached at one end to said crank and atthe other end to said gear by a movable conneciion whereby its saidlast-named end is compelled to move radially to said gear, a fixedsupport carried by the bicycle-frame and having a slot or guideway and aloose fulcrum received and retained in both slots and located betweenthe said crank and said gear, substantially as described.

6. In a bicycle, a pedal-crank, a gear actuating the driving-axle, alever having a 1011- gitudinal slot and attached at one end to saidcrank and at the other end to said gear by a movable connection wherebythe said lastnamed end is compelled to move radially to said gear, afixed support carried by the bicycle-frame and having a slot or guidewayand a loose ball received and retained in both slots, located betweenthe said crank and said gear, and serving as a movable fulcrum for saidlever, substantially as described.

CHAS. O. PROTI'IEROE.

'Witnesses:

JAMES T. NELsoN, ALmoK W. MUN.

